From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham
	autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,9b2046241520981f
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2003-07-28 05:39:28 PST
Path: 
 archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!newsfeed.icl.net!newsfeed.fjserv.net!newsfeed.freenet.de!fu-berlin.de!uni-berlin.de!82-43-33-75.cable.ubr01.croy.blueyonder.co.UK!not-for-mail
From: "Nick Roberts" <nickroberts@blueyonder.co.uk>
Newsgroups: comp.lang.ada
Subject: Re: Ada 0x, exception idea ?
Date: Mon, 28 Jul 2003 13:41:29 +0100
Message-ID: <bg35hv$kddvv$1@ID-25716.news.uni-berlin.de>
References: <3F229597.3090909@myob.com>
 <mailman.5.1059306172.320.comp.lang.ada@ada.eu.org>
 <bg0r8r$j4rid$1@ID-25716.news.uni-berlin.de> <87smorj3kp.fsf@inf.enst.fr>
NNTP-Posting-Host: 82-43-33-75.cable.ubr01.croy.blueyonder.co.uk (82.43.33.75)
X-Trace: news.uni-berlin.de 1059395967 21411839 82.43.33.75 (16 [25716])
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 5.50.4807.1700
X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4807.1700
Xref: archiver1.google.com comp.lang.ada:40897
Date: 2003-07-28T13:41:29+01:00
List-Id: <comp.lang.ada>

"Samuel Tardieu" <sam@rfc1149.net> wrote in message
news:87smorj3kp.fsf@inf.enst.fr...

> How would you integrate this with Ada.Exceptions.Raise_Exception?
> (to attach an error message to the exception occurrence)
>
> RAISE [exception_name] WITH [exception_message] [WHEN expression] ?
> Would expression be evaluated before or after exception_message? Would
> exception_message be evaluated at all if the test is wrong?

I don't think I would want to go so far, and I'm 99% certain the ARG
wouldn't even consider it (for the next revision). If you want a message,
you just have to write:

   if condition then
      Ada.Exceptions.Raise_Exception(exception'Identity,message);
   end if;

Too bad. I think a typical debugging package would have an inlined procedure
such as:

   Ensure( condition[, message] );

which would test the 'condition', and raise e.g. Debugging_Error if it is
false, setting the exception's message to 'message' if supplied.

--
Nick Roberts
Jabber: debater@charente.de [ICQ: 159718630]